PIR Motion Sensor

It is great for microcontrollers such as arduino for funduino and many more including the rasberry pi!

It is a HC--SR501 Sensor Module

With an operating voltage of 5v to 20v

Operating voltage. It has a high value of 3.3 volts and a low of 0 (it is either on or off). It's delay time can be adjusted from 5 to 200seconds as well as the sensing range from 3meter to 7meters. The entire sensor with the board is 32mm by 24mm (standard pir motion sensor). The sensor either gives off a 3.3volt high value when motion is detected and then resumes or continues to give off a 0 voltage when no motion is detected. If you use an arduino or other micro controllers you can use the 3.3 volt out to power the sensor or use the 5volt power pin (vcc) to power the sensor. Either one will work.